"The rumors are true," a source close to the show told the website, confirming that Jackson will take his seat alongside newcomer Mariah Carey and one or two other judges who have yet to be chosen.

Yesterday, former Idol judge Simon Cowell seemed to confirm the speculation, tweeting, "Just heard randy is back on idol. Right decision."

A representative for Fox declined to comment.

Rumors surrounding Jackson's ongoing Idol involvement have been swirling during the show's rather busy off-season, which saw the departures of judges Steven Tyler and Jennifer Lopez, and the recent addition of Carey. It was thought that Jackson – the show's only remaining original judge – might step down from his position and take on an undefined "mentor" role.

Now, of course, the question is who will join Jackson and Carey as judges. Speculation has recently centered on Nicki Minaj, but the rapper was coy about her involvement when asked about the new gig during a red-carpet interview last week at the MTV Video Music Awards: "You know something, I don't know yet. I really don't know. I have no comment on it."